The present invention relates to shaped metal component production technology and, more particularly, to a sheet metal member shape forming system and method for molding a thin sheet metal member into a shaped metal component using compression molding.
Following prospective sales of 3C-information products and high-end home appliances around the world, metal shell bodies have already become basic housing for many commodities. Conventionally, there are three different sheet metal member shape forming techniques: stamping forming, vacuum forming, and compression molding. FIG. 1 is a schematic structural view of a conventional sheet metal member shape forming system.
The aforesaid prior art sheet metal member shape forming system 10 comprises a mold 11 consisting of a sealing die 111 and a shape-forming die 115. The shape-forming die 115 is placed on a worktable 19. The sealing die 111 defines therein a sealing cavity 112 and an air hole 175. The shape-forming die 111 defines therein a shape-forming cavity 116. Further, an electric heating coil 13 is arranged around the sealing die 111 and the shape-forming die 115. The electric heating coil 13 controls the heat of the mold 11 and a sheet metal member 15 that is placed within the mold 11. When the temperature of the sheet metal member 15 reaches a predetermined temperature, a high-pressure gas generator 171 is controlled to generate a high-pressure gas 179 and supplies the high-pressure gas 179 through a gas delivery pipe 173 and the air hole 175 into the sealing cavity 112. At this time, the high-pressure gas 179 gives a gas pressure Pa to the heated softened sheet metal member 15, abutting the softened sheet metal member 15 against the inner surface of the shape-forming cavity 116 subject to the effect of the gas pressure Pa, thereby forming a shaped metal component 155.
When the sheet metal member shape forming system guides the high-pressure gas 179 into the sealing cavity 112, only the holding force of the worktable 19 or the clamping force of the mold 11 can resist the gas pressure Pa in the sealing cavity 112 of the mold 11. At this time, the high-pressure gas 179 may leak out, affecting the molding speed and quality of the shaped metal component 155.
Further, if the sheet metal member 15 is directly moved from a room temperature condition into the mold 11 for heating, the high-pressure gas 179 can be applied to the inside of the sealing cavity 112 only after the sheet metal member 15 has been heated to a predetermined temperature. It takes much time to heat the sheet metal member 15 to the predetermined temperature in the mold 11, affecting the mass production speed of the shaped metal component 155.
There is known another prior art sheet metal member shape forming system, which preheats a sheet metal member 15 outside the mold 11, and then puts the pre-heated sheet metal member 15 in the mold 11 for continuous heating and further compression molding, shortening the molding speed of the desired shaped metal component 155. However, when moving the preheated sheet metal member 15 into the mold 11, the temperature of the sheet metal member 15 will fall. After the sheet metal 15 has been put in the mold 11 and heated again, the temperature of the sheet metal member 15 will rise again. Severe temperature fluctuation of the sheet metal member 15 will affect the quality of the shaped metal component 155.
Therefore, the aforesaid prior art sheet metal member shape-forming systems have the drawbacks of: easily causing product surface damage during production, being difficult to improve the molding speed, having a low yield rate, and requiring a secondary processing process due to the non-precision metal outer surface. Therefore, the prior art sheet metal member shape-forming systems and methods have room for improvement.